Tablets now represent 21% of requests, compared to 10% just 12 months ago.
A jump of six percentage points took place between November 2012 and January 2013, when the tablet use reached 18%, and the figure has been growing ever since.
The casualty is PC viewing, which may also have been hit by slight increases in connected TV and TV platform viewing.
Sport boosted live viewing on the BBC catch-up service in July, with the proportion of live requests to TV and radio both up month-on-month to 15% and 85% respectively
A record 77 million radio requests were made in July, with requests from mobiles the highest they have ever been.
Driving the increase was BBC Radio’s coverage of The Ashes cricket between England and Australia – with the live TV rights firmly in the hands of Sky Sports – who can also be expected to have found success for The Ashes on its Sky Go service.